1. Field of the Invention
The present invention relates to an electronic stereo clino-compass, for use in construction and civil engineering works, which measures a plane in a three-dimentional space, that is, an azimuth angle and an angle of inclination with respect to a horizontal plane normal to the direction of gravity.
2. Description of the Prior Art
Measurements of the direction and inclination of a normal surface in civil engineering works, measurements of direction and inclination of items such as pillars and floors in construction works and measurements of deformation of pillars and floors in house investigations are performed by human labor using precise surveying techniques as will be described later. In the measuring the azimuth angle of a discontinuous surface of a stratum in geological investigations (the so-called "strike" in the field of geology) and the angle of inclination (the so-called "dip" in geology), a mechanical clino-meter as will be described later has been used.
However, the above-mentioned conventional measuring technology has the following drawbacks.
(1) Where a precision survey is performed:
(a) It is necessary to have an engineer who is skilled in survey technology. PA1 (b) Much time is required for the survey and data processing. PA1 (c) The process requires two persons of whom one takes the measurements and the other carries with him position targets to the survey points, respectively. PA1 (d) With house investigations, it is difficult to get a high-precision survey since an object to be measured is small and narrow. PA1 (a) A certain degree of special knowledge of the field of this measurement technique is required to put the angled part of the clino-meter on a discontinuous surface of a stratum to measure the running direction (i.e., azimuth angle), and then target the side surface which is at right angles to this surface to measure the inclination. PA1 (b) Using a spirit level to take level measurements means that the accuracy of the level measurements is low, as does the use of roughly marked compasses. PA1 (c) Precision is lost over long periods of use due to general wear, such as friction and corrosion of the compass slider. PA1 (d) Time is required for the position of the magnetic pointer to settle. Time is also required for the person taking the measurements or an assistant to record data after taking the measurements. This means that a substantial period of time is required to take only one measurement. Also, if the person taking the measurements is changed, then another person taking the next measurements may take them in a slightly different way, so that the measurement precision is not stable. PA1 (e) The glass face of the compass is easily damaged, and will be damaged by an impact caused by dropping, for example. PA1 (f) As it is of a mechanical structure, it has a low resistance to impacts.
(2) Where a clino-meter is used: